Samsung needed something big this in 2015, a phone that could reboot its fortunes without completely changing what the company stands for. And it's largely managed to do just that, building on its strengths while smoothing off some of the rough edges from before.

It's not perfect, and there are some issues (like battery and price) that still need to be really thought about before purchase, but Samsung has mostly done what it needed to with the S6.

We liked

When I first saw the Galaxy S6 I was immediately impressed. It was like someone walked into the boardroom of Samsung HQ, picked up the S5 and tore it to pieces, before delivering a more grown up version based on the things consumers actually want.

The metal and glass combination was easily the best thing the brand has ever created in the smartphone space (though it's since been refined on the Galaxy S7 and Galaxy S8), and needs to trickle down to the lower-end and tablet ranges too.

The camera is also a particular highlight, coming up with some of the most glorious images I've ever seen on a smartphone. It's not the best in terms of out and out quality, but for a mainstream phone it perfectly blends photographical prowess with operational simplicity.

The screen on the Galaxy S6 is still superb, and the QHD improvement does deliver a few benefits - it's certainly not diminished anything visually. The ergonomics and weight of the phone mean it sits very well in the hand, making it perfect for watching a load of TV shows or just carrying around for music.

It's also got a good gaming prowess, and the interface is refined to a point where it's much less intrusive. In short, all the good bits are now gooder and the poor bits less poor.

We disliked

OK, not ALL the good bits are gooder. Battery life on the Galaxy S6 isn't good enough for a phone of this caliber or price. I don't think anyone should be worrying about whether their new expensive smartphone will still be able to make emergency calls when it's a bit later in the evening, and that's what the S6 offers.

I've not talked about Ultra Power Saving Mode in this review, as I think that it shouldn't be lauded as an option. If your phone could maybe squeak two days on battery then I think an option to extend it is a great thing, but given I was considering turning it on daily I was unimpressed.

The price has also risen again, which is annoying. I've lambasted Apple for prices that are too high in the past, and now Samsung has sailed right past that cost point. There's a lot of technology on offer here, sure, but not enough to make it this much more than Apple.

The construction of this thing must cost a huge amount, otherwise Samsung is just charging more to make the device seem more premium and bolster the bottom line, and I really hope that's not the case.

Oh, and if you go for a non-white version of this phone, beware of the millions of fingerprints you'll get. They just appear all over the phone instantly. You'll have to get a good case, carry around a cloth at all times or just not use your fingers ever. Your call.

Verdict

When I first walked into the subterranean hotel room and caught sight of the Galaxy S6, I was entranced. This was the phone that I'd wanted Samsung to make for years, and it was finally here: a perfect blend of design and extreme power.

The only worries I had back then were the battery life and price, and sadly these are the big reasons why it can't get a perfect score. You'll be able to get around them if you really want the phone (kidneys can still be sold, right?) but for a flagship phone I expected better, especially in terms of battery life.

Nobody has convinced me that we need QHD screens yet, and it seems that could be one of the real problems with the S6 and it running out of power so easily.

But don't let the above take away from the utterly brilliant bits of this phone: the camera is SUPERB, the build quality excellent and the speed under the finger second to none at times.

This is the best Android phone of 2015, and well worth thinking about if you're after a really cutting edge device (and can afford it).

The Samsung Galaxy S6 now has a full compliment of rivals to face off against - these are some of the best alternatives on the market.

Samsung Galaxy S8

The Samsung Galaxy S6 is over two years old now, and it's starting to show its age. If you're looking for the latest flagship phone from Samsung you'll want to check out the Galaxy S8.

It improves on the Galaxy S6 is pretty much every way, with a stunning 5.8-inch Infinity Display, great camera and a whole heap of power.

Thing is, it is expensive. Really expensive. If your budget can't quite stretch to the Galaxy S8, then the S6 will be a tempting offer - but we'd recommend taking a look at the Samsung Galaxy S7 first, which has also witnessed a price drop since the S8's arrival.

iPhone 6S

The Samsung Galaxy S6 sits between the iPhone 6S and the iPhone 6 in terms of when it was released, but as Samsung's main 2015 flagship it inevitably has to compete with the iPhone 6S now.

It's easily up to the task too, despite being a little older. Both have largely the same battery life and both offer no expandable memory with three storage options (although the base model of the S6 is 32GB to the iPhone's 16GB).

But following price drops the Galaxy S6 is closer in price to the iPhone 6 now than the expensive iPhone 6S.

It also has Apple's phone beaten on specs, with a superior camera and a QHD screen, where the 6S can't even manage 1080p.

Still, Apple's handset is just as stylish, with a simpler interface, better apps and new features, like 3D Touch, so it's a strong alternative if iOS is more your bag.

HTC One M9

I feel, in many ways, the Galaxy S6 is the Will.i.Am to HTC's David Bowie. One's more cultured, the other newer with more tricks. One is based on older ideas, but still has the air of refinement. The other, well... Actually, no, this analogy is getting too tortured. Basically I'd rather own an S6 than listen to a Will.i.Am track.

HTC has launched a very similar phone to the previous year with the One M9, although it's still a very good handset. The design is still miles ahead of Samsung's, the battery life the same, and the screen not too far off - although it lacks the sharpness.

It's in the base power that HTC suffers - Samsung's got a lot of the basics right, more so than its Taiwanese rival, with an improved camera the real highlight.

HTC's offering is cheaper though, despite being made out of more premium materials, so if you can see past the fact it's a very similar phone to last year, it's a very good choice.

Samsung Galaxy S6 Edge

This should be an easy decision for most of those deciding between the S6 and the curved edge variant: can you afford it? It's a lot more money both on contract and SIM free, and apart from having a battery that's fractionally larger and a bent screen at each side, there's not a lot of benefit.

It certainly looks cooler, a spacephone in a sea of identikit black slabs, but the screen also makes it less comfortable to hold. It's more status symbol than anything else, albeit it one with all the brilliant bits of the S6 underneath.

Sony Xperia Z5

The Sony Xperia Z5 really feels like the fresh phone the company needed. The battery life, as usual from Sony, is pretty great and a definite improvement on what the Galaxy S6 offers.

It also has a top flight fingerprint scanner, just like Samsung's phone and the design has been refined since the Sony Xperia Z3+ to make it light, slim and almost as stylish as the Galaxy S6.

I'm not quite as sold on the Z5's camera as the S6's, though there's certainly a lot of power here, and the phone lacks a little in some areas. The screen is just 1080p for example. But this is easily the best handset Sony has ever made and with a waterproof shell and a microSD card slot it can deliver things that the Galaxy S6 can't.